1. Technical Field
The present invention relates to liquid ejecting heads and liquid ejecting apparatuses.
2. Related Art
A known example of a liquid ejecting head is an ink jet head that ejects ink droplets from a nozzle opening by applying pressure to ink within a pressure chamber that communicates with the nozzle opening. When bubbles enter into a reservoir (common liquid chamber) that communicates with a plurality of pressure chambers, during printing those bubbles may enter into individual flow channels leading to the nozzle openings. This can result in missing dots, where ink droplets are not ejected from the nozzle opening, which reduces print quality. Accordingly, a cleaning process is carried out to discharge bubbles from within the reservoir. In this cleaning process, an interior space formed by the ink jet head and a cap is depressurized in order to forcefully suck ink from the nozzle openings.
In an ink jet head disclosed in JP-A-2-52745, protrusions are provided in the vicinity of an entrance into which the ink flows from an ink tank into the reservoir so that the flow of ink within the reservoir does not stagnate and bubbles within the reservoir can be smoothly discharged to the exterior of the head.
Configurations that reduce the size of the reservoir are in demand for the purpose of miniaturizing the ink jet head. However, when the size of the reservoir is reduced, the flow channels are also narrowed as a result, making it easier for bubbles to accumulate within the reservoir. Accordingly, bubbles within the reservoir may not be discharged even if a cleaning process is carried out. Note that this problem is not limited to ink jet heads, and occurs in various types of liquid ejecting heads and liquid ejecting apparatuses as well.